Method for Manufacturing an Industrial Clothing

ABSTRACT

An industrial clothing, in particular a clothing for a machine for manufacturing a fibrous web, such as a paper, cardboard, or tissue web, or a non-woven product, is manufactured by: i) forming a planar structure from yarn in the form of a woven fabric, a cross-laid structure, a knitted fabric, a warp-knitted fabric; or from interconnected helical elements; ii) applying polymer material in the form of at least one group of beads to at least one surface of the planar structure, the application of the polymer commencing at starting points and terminating at terminal points remote from the starting points; iii) repeating step ii), wherein terminating points of the group of beads are spaced apart from starting points of at least one further group of beads, which generates regions with a void between the groups on the surface of the planar structure.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of patent application Ser. No.14/784,094, filed Oct. 13, 2015; which was a § 371 national stage filingof international application No. PCT/EP2014/057131, filed Apr. 9, 2014,which designated the United States; this application also claims thepriority, under 35 U.S.C. § 119, of German patent application No. DE 102013 206 278.8, filed Apr. 10, 2013; the prior applications are herewithincorporated by reference in their entirety.

BACKGROUND OF THE INVENTION Field of the Invention

The invention pertains to a method for manufacturing an industrialclothing which may be used for example in various positions in a machinefor manufacturing a fibrous web, such as a paper, cardboard, or tissueweb, or else for manufacturing non-wovens, and to an industrial clothingwhich is manufacturable by a method of this type.

Clothings for large-scale industrial plants such as paper machines ormachines for manufacturing non-woven products are usually manufacturedfrom a polymer monofilament yarn from which a planar structure isgenerated for example by weaving or coiling. On account thereof, acarrier structure which is to correspond to specific requirements interms of properties and functions in order to enable manufacturing ofthe respective paper quality is obtained. The carrier structures supportthe fibrous web while the latter runs through the fibrous-web machine.

A plurality of various sections which during the manufacturing processfulfill various tasks are usually present in a machine of this type formanufacturing a fibrous web. Therefore, various requirements which arereflected in various features are thus set for the clothings. Manyclothings have a permeable and flexible structure, so as to enableliquid to pass through during de-watering, while the cellulose fibers ofthe material are simultaneously oriented and commence forming thefibrous web. Other clothings are less complicated in their constructionand have higher air permeability. Drying wires convey the paper webthrough the dryer section and simultaneously permit dissipation of watervapor during the drying process.

Woven structures may also be manufactured such that they have a certaindegree of topography or structure on that side that faces the paper.This may be in the form of a pattern of line elements which is dominantin the machine direction or in the machine cross direction, or in theform of a single pattern or motif.

The surface structure may be transferred from a clothing to the paperweb during the manufacturing process, such that a permanent structure isvisible in the finished product.

A significant disadvantage when using weft or warp threads in themanufacture of such topographic patterns lies in the complexity of theweaving patterns for generating a specific visual or structural effect.In terms of the manufacturing operation of the clothing, this meanslosses in time efficiency during manufacture, higher costs, limitationswith respect to the freedom of design and the balance betweenfunctionality and aesthetic considerations in the clothing, and higherreject rates on account of the complex patterns. Moreover, line-shapedpatterns are limited to the machine direction, the machine crossdirection, or to a twill weave.

Patterns of this type and the methods for generating the same have beenknown in the prior art in a multiplicity of variations for a long time.

For some time, patters on the surface of clothings are also generated byprinting, for example using a polymer which is applied to the clothingby means of various methods and fixed thereon. In this way, it is knownfrom EP2304104B1 to use a rotary screen for generating a topographicpattern from a polymer material on an endless belt, the cylindricalsleeve face of said rotary screen having a perforated pattern whichdetermines the topographic pattern and which, when viewed in thecircumferential direction of the sleeve face, is formed by a perforatedpattern portion or by a plurality of perforated pattern portions whichlie in sequence and are mutually identical. In order for the pattern tobe generated on a circumferential side of the endless belt, the polymermaterial in a liquid or pasty state is squeezed through perforations ofthe sleeve face of the rotary screen while the rotary screen, turningabout is longitudinal axis, rolls in a continuously revolving path onthe circumferential side of the endless belt.

DE 10 2005 006 738 A1 likewise discloses a method in which a topographicpattern on a paper machine clothing is generated by means of a rotaryscreen.

Combinations including topographic weaving patterns and patterns whichare printed thereonto and superimpose the former are also known, forexample from EP1242681B1. Here, a fabric which is used in a paper-makingmachine in order for a pattern to be formed on a tissue paper isdescribed. The fabric comprises a load-bearing layer which defines afirst plane, and forming layer which is interwoven with the load-bearinglayer and defines a second plane which is spaced apart from the firstplane, wherein the upper side has a background texture which is definedby the load-bearing layer and the forming layer. A polymer strand isdisposed in a decorative and thread-like pattern on the upper side, thebackground texture appearing where the pattern formed by the polymerstrand does not appear.

The methods mentioned here have various disadvantages. In the rotaryscreen method it is disadvantageous that no formations of comparativelygreat length are manufacturable if the size of the screen is to bewithin manageable limits. The combined fabric and polymer patterns arecomplex in their manufacture. The freedom of design in terms of thedimensions of the polymer application is not ensured either, but ratheris limited by further limiting factors such as the screen thickness andmay not be implementable in the desired manner in all fields ofapplication. For example, it is not possible for polymer to be appliedin any arbitrary thickness, or height above the screen surface,respectively, since the thickness of the material is correlated to thatof the screen.

Moreover the design of the polymer application across the extent of theclothing cannot be varied when the rotary screen printing method isused, despite it being desirable in many cases, for a polymerapplication which in the peripheral regions is different than in thecentral part of the clothing to be attached, for example.

BRIEF SUMMARY OF THE INVENTION

Accordingly, it is an object of the invention to mitigate or avoid thedisadvantages of the prior art and to state a method for manufacturingan industrial clothing and an industrial clothing which on the one handis manufacturable such that the fundamental physical properties such asdimensional stability and air permeability are ensured and on the otherhand patterns in the desired shape and number may be readily applied tothe clothing.

This object in terms of the method is achieved by the claimed method,and in terms of the industrial clothing by the claimed clothing, in eachcase in conjunction with the generic features.

According to the invention, it is provided that in a first method stepmanufacturing a planar structure from yarn in the form of a wovenfabric, a cross-laid structure, a knitted fabric, a warp-knitted fabric,or from interconnected helical elements is performed. In a second methodstep at least one polymer material in the form of at least one group ofbeads is applied to at least one surface of the planar structure, theapplication of the polymer commencing at starting points and terminatingat terminal points which are remote from the starting points. Thismethod step is repeated arbitrarily, wherein terminating points of theat least one group of beads are spaced apart from starting points of atleast one further group of beads, on account of which regions with avoid between the groups on the surface of the planar structure aregenerated.

On account thereof, beads which are of arbitrary length and number maybe manufactured in arbitrary patterns, combinations, and shapes, on theone hand, which beads on the other hand are interrupted at arbitraryspacing and, on account thereof, define regions with a void, so as to,on account thereof, achieve space for further patterns, motifs, logos,etc., which may be readily incorporated into the regions with a void ina further method step or else simultaneously with the beads.Combinations of patterns of an arbitrary variety and having propertiesof the final product in terms of strength, thickness, air permeability,etc. which are adjustable in an almost unlimited manner may thus beenabled.

According to one advantageous aspect of the invention, all beads have alength which corresponds to at least double the maximum width thereof.The width of the bead may be considered to be the width on the surfaceof the planar structure, for example.

In one further advantageous embodiment of the method according to theinvention, the application of polymer is performed by means of at leastone application nozzle. By way of an application by a nozzle, beadswhich are short as well as of an arbitrary length may be applied withoutparticular technical complexity. The application of polymer ispreferably performed by way of a plurality of application nozzlessimultaneously. An arbitrary number of application nozzles operatedsimultaneously are conceivable. In one particularly preferred embodimentthe application of polymer is simultaneously performed by means of 5 to100 application nozzles. The plurality of application nozzles may bedisposed in the machine cross direction so as to be beside one anotherand so as to be fixedly spaced apart. This spacing may be identical forall application nozzles or else be variable. Advantageous spacingsbetween the application nozzles are between 0.5 mm and 20 mm.

In one further advantageous embodiment the application nozzles areactuated individually or in sets. In this way, the application ofpolymer of the individual application nozzles or sets of applicationnozzles may be independently activated or deactivated, respectively,and/or regulated. In the context of the invention one set here comprisesa plurality of application nozzles, preferably between 2 and 50application nozzles. One application nozzle here may always beassociated with at maximum only one set. The application nozzles of aset here may either be directly adjacent to one another or be mutuallyspaced apart in a fixed manner, such as, for example, to include everytenth or twentieth nozzle. However, it is also possible for a set tocomprise a non-uniform selection of application nozzles.

Actuating the application nozzles in sets offers advantages in economy.In this way, only 10 valves are required for actuating 100 applicationnozzles which are grouped into 10 sets.

An industrial clothing according to the invention, in particular aclothing for a machine for manufacturing a fibrous web, such as a paper,cardboard, or tissue web, or a non-woven product, is an industrialclothing which has been manufactured according to one of the methodsaccording to the invention.

According to one advantageous aspect of the invention, the beads and/orthe regions with a void may be configured in the form of patterns orvirtual patterns.

The beads are preferably applied along tracks. The individual trackshere run in a uniform manner and beside one another in the machine crossdirection. There is a spacing here between two adjacent tracks, whichspacing along the profile of the track remains substantially constant.Variations may arise here within the scope of production accuracy. Inone particularly preferred embodiment, all spacings between the tracksare of identical size.

The tracks here are to be understood to be like grid lines on which thepolymer beads are deposited. Many of the tracks may be completelycovered with polymer. Other tracks contain one or more regions with avoid between the individual beads. The potential for individual tracksbeing entirely without an application of polymer may also be provided.

The tracks may particularly preferably run in a straight, undulated, orzigzag manner. However, other variants of a uniform profile are alsoconceivable.

The tracks may preferably have the full length of the circumference ofthe industrial clothing. There is also the possibility for the tracks tohave an even greater length, up to a multiple of the circumference ofthe industrial clothing. This is the case with a helically encirclingprofile of the tracks. In this way, a helical profile of the tracks isconceivable, for example, in that the mounting having the applicationnozzle or application nozzles, respectively during application is movedin the machine cross direction such that said mounting after onerevolution of the industrial clothing is offset in the machine crossdirection by its own width.

It is also advantageous for the pattern to be constructed from at leastone digital image motif. In the context of this patent application adigital image motif is understood to be a motif which, in an analogousmanner to usual digital images, is composed of a finite number ofdiscrete color values. A digital image motif in the context of theinvention here is formed by beads and regions with a void. The beadscorrespond to line-shaped color spots and the regions with a voidcorrespond to white spots. If only one type of beads is used, thedigital image motif corresponds to a black and white image. If differenttypes of beads are used, the digital image motif in an analogous mannerto a digital image has a plurality of gray scales.

The digital image motif has an extent in the machine running directionand the machine cross direction. Said digital image motif forms the coreof the pattern. The pattern per se is created by repeating the at leastone image motif. In one preferred embodiment the pattern is created byway of tessellation of the entire surface of the industrial clothing, orat least parts thereof, using the digital image motif.

The digital image motif in one preferred embodiment in the machine crossdirection prior to a repeat of the motif commencing extends across atleast two beads and/or regions with a void, or across at least twotracks, respectively, in one particularly preferred embodiment thedigital image motif embodiment extends across at least three beadsand/or regions with a void, or across at least three tracks,respectively, and in a very particularly preferred embodiment thedigital image motif embodiment extends across at least five beads and/orregions with a void, or across at least five tracks, respectively.

In one further advantageous embodiment the extent of the digital imagemotif in the machine cross direction prior to a repeat of the motifcommencing is at maximum 10%, preferably at maximum 5% of the width ofthe industrial clothing.

According to the two preferred embodiments which have just beendescribed above, the digital image motif in the machine cross directionis thus considerably wider than one individual bead. However, incomparison with the industrial clothing, said digital image motif isstill small in the sense that it may be disposed frequently, for examplemore than 10 times or more than 20 times, across the width of theindustrial clothing.

In one further preferred embodiment at least two types of beads areapplied on the industrial clothing, which types of beads differ in atleast one of the parameters of material, cross-sectional shape, andcross-sectional size. These different types of beads in the fibrous webmay lead to various or variously pronounced effects, respectively. Thismay be utilized for functional or decorative purposes. A digital imagemotif which is constructed from regions with a void and from two typesof beads, for example, may thus be considered to be an image motif withthree colors.

The polymer may advantageously be a silicone, a polyurethane, an epoxyresin, or an ester. The mentioned materials in terms of theirprocessability and shelf life are easily manageable and available inbulk quantities.

It may be preferably provided that the polymer is linked to the surfaceof the clothing in a form-fitting and/or materially integral manner. Onaccount thereof, it is ensured that the beads adhere thereto in areliable manner, and that the clothing is capable of being used for along time without material flaking off therefrom.

According to one advantageous aspect of the invention it may be providedthat the beads are configured so as to be flush with a surface of theindustrial clothing. This is advantageous in particular for formingwires for manufacturing watermarks.

However, according to one alternative variant of a design embodiment itmay also be provided that the beads protrude above the surface of theindustrial clothing in a direction z. On account thereof, thestructuring embossed in the fibrous web becomes more visible.

The height of the beads in the direction z is preferably up to 2 mm. Inother advantageous embodiments the height of the beads in the directionz may be up to 5 mm. On account thereof, it is possible for clear andsharply delineated structures which are deeply embossed in the fibrousweb to be achieved.

A ratio between the height in the direction z and the width of the beadsmay preferably be between 0.5:1 to 2:1, preferably be 1:1. Variationstherefrom may lead to instability of the beads, damage, and flaking,potentially compromising the quality of the final product.

The invention will be described in the following in an exemplary mannerwith reference to the figures in which:

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIGS. 1 to 3 show exemplary embodiments in which beads are depositedaccording to the invention along tracks, and the pattern is formed byrepeating a digital image motif.

DESCRIPTION OF THE INVENTION

Highly schematic exemplary embodiments of patterns 6 which are appliedto an industrial clothing which is not illustrated in detail areillustrated in FIGS. 1 to 3. Only a small detail of the pattern 6, whichis further repeated both in the machine running direction 7 as well asin a perpendicular manner thereto in the machine cross direction, is ineach case shown in the three figures.

The patterns 6 are created according to the invention by regularlyrepeating a digital image motif 5. The image motif 5 in the threefigures is in each case composed of beads 1 and regions with a void 3.

The beads 1 in FIGS. 1 to 3 are in each case deposited along tracks 10.In FIGS. 1 and 3 the tracks run in a straight manner along the machinerunning direction 7, in FIG. 2 the tracks 10 run in a zigzag manner alsosubstantially along the machine running direction 7. However, the tracks10 may also run in an undulated manner or in other shapes. In the caseof further embodiments according to the invention the tracks 10 run at aslight angle to the machine running direction 7. In this way it may beachieved that the tracks 10 encircle the industrial clothing in amultiple helical manner. Beads 1 which are longer than the circumferenceof the industrial clothing may then also be deposited on such tracks 10.

The tracks 10 in FIGS. 1 to 3 all have an identical spacing 4 from therespective adjacent track. The spacing 4 here also remains constantacross the entire length of the track 10 even in the case of the zigzagtracks 10 in FIG. 2, disregarding minor variations caused by theproduction technology. However, there is also the potential for thetracks 10 to have variable mutual spacing's 4.

As shown in FIG. 1, the beads in one digital image motif 5 may all havethe same length. FIGS. 2 and 3 however also show embodiments accordingto the invention, in which the beads 1 have variable lengths. Regionswith a void 3 in the digital image motifs 5 are created by interruptions2 of the beads 1.

The digital image motif 5 in FIGS. 1 and 2 has a width in the machinecross direction of eight tracks. FIG. 3 shows a digital image motif 5having a width of five tracks 10, wherein one track 10 has no beads 1deposited thereon.

The industrial clothing here may be a forming wire, a base fabric of apress felt, a drying wire, a transfer belt, or any further arbitraryclothing. The mentioned clothings may be disposed in various positionsin machines for manufacturing a paper, cardboard, or tissue web, or elsein machines for manufacturing non-wovens. As has already been mentionedabove, various requirements in terms of water permeability, tensilestrength, resilience, open volume, etc., are set for the clothing,depending on the position thereof.

The clothings may be configured in a sufficiently known manner in theform of woven or non-woven structures. The planar textile structureswhich form the clothings are usually manufactured by interweaving warpand weft threads. Clothings which are entirely or partially composed ofnon-woven components, such as cross-laid structures, knitted fabrics orwarp-knitted fabrics, are also known and suitable for application of themeasures according to the invention. The planar textile structures maylikewise be manufactured by coiling a tape-like material or skeins ofthreads. Finally, forming clothings by interconnecting helicalstructures by means of pintles is also known, the latter being usual inparticular in the field of drying wires. The clothings may be combinedin a known way with further components, such as staple-fiber layers orpolymer proportions in the form of films or particles, so as to furthermodel the profile of the properties.

The pattern 6 or else a virtual pattern, which is applied repeatedly orwithout a specific repeat to at least one surface of the planar textilestructure, here is composed of beads 1 from a polymer material, such assilicone, polyurethane, epoxy resin, or esters, for example.

Each of the beads 1 here has a specific length L between a startingpoint and a terminating point of the respective bead 1. Theinterruptions 2 lie in each case between terminating points of one or aplurality of beads 1 and starting points of further beads 1. The regionswith a void 3 may assume any arbitrary shape, depending on how themutual spacing of the individual beads 1 is conceived. Patterns 6,virtual patterns, or arbitrary arrangements of regions with a void 3 maybe generated.

In a further step of the manufacturing method these regions with a void3 may then be provided with a further polymer pattern which may be apersonalized motif or a logo, for example.

The pattern 6 here may be selected for aesthetic and/or practicalconsiderations, the latter influencing the physical properties of thefibrous web, for example.

The topography of the beads 1 may vary depending on the respective fieldof application of the clothing as well as on the thickness and thegrammage of the product. The beads 1 may lie in the plane of theclothing surface or protrude above the latter by a certain height in thedirection z of up to 5 mm. The width of the beads 1 here depends on theheight in the direction z. The ratio of height to width will typicallybe in a range of approx. 0.5:1.0 to 2:1. A ratio close to 1:1 iscurrently preferable, so as to ensure an optimal shape of the beads 1.The spacings between the individual beads 1 are preferably at least ofthe same size as the width of said beads 1.

The polymer adheres to the surface of the clothing by way of acombination of form-fit and material integrity. Form-fitting here isobtained by way of the threads of the planar textile structure byencasing said threads with a polymer. The material combination ofclothing and polymer may optionally also form a chemical bond and, onaccount thereof, enable material integration. Pre-treatment of theclothing for the purpose of improving adhesion of the polymer to theclothing, for example by way of plasma activation, is likewise possible.

1. A method for manufacturing an industrial clothing, the methodcomprising the following method steps: i) manufacturing a planarstructure from yarn in the form of a woven fabric, a cross-laidstructure, a knitted fabric, a warp-knitted fabric, or frominterconnected helical elements; ii) applying at least one polymermaterial in the form of at least one group of beads to at least onesurface of the planar structure, thereby commencing at starting pointsand terminating at terminal points that are remote from the startingpoints; iii) repeating step ii) and generating on the surface of theplanar structure regions with a void between the groups of beads byspacing apart terminating points of the at least one group of beads fromthe starting points of at least one further group of beads.
 2. Themethod according to claim 1, wherein a length of individual beads is atleast twice a maximum width thereof.
 3. The method according to claim 1,which comprises applying the polymer with at least one applicationnozzle.
 4. The method according to claim 3, which comprises applying thepolymer with a multiplicity of application nozzles.
 5. The methodaccording to claim 4, which comprises actuating the application nozzlesindividually or in sets, and applying the polymer of the individualapplication nozzles or of the sets of application nozzles withindividual activation or deactivation, wherein the sets comprise between2 and 50 application nozzles.
 6. The method according to claim 1, whichcomprises manufacturing a clothing for a machine for manufacturing afibrous web selected from the group consisting of paper, cardboard,tissue web, and a non-woven product.
 7. The method according to claim 1,which comprises applying beads of the groups of beads along tracks in amachine running direction with individual tracks thereof runninguniformly and with adjacent individual tracks having a constant spacingbetween one another in a cross direction to the machine runningdirection.